1. Field of the Invention
This invention relates to a hand held apparatus intended to be used by golfers to measure a golf ball's compressibility, or hardness, and also the sphericity of the ball.
2. Description of Prior Art
The Compression Ratings used for golf balls have been in use since the 1940's and it has become commonly accepted that a rating of 100 is harder than 90. This practice is still the norm for today's balls. Originally, manufacturing methods had difficulty in producing balls with consistent hardness and quality and therefore the testing and rating systems were devised. The manufacturing process produced balls with a wide range of hardness and the harder balls were actually those balls which were produced when the manufacturing process was working at it's best. These balls were considered to be higher quality and were more costly to the golfer. For this reason, harder balls were considered to be better than the softer balls. These balls were manufactured using what is today referred to as a three part construction; a central core, a wound middle core and a soft balata cover.
Previous patents relating to this field are:
U.S. Pat. No. 2,278,416 to Atti (1942). This patent describes a portable test apparatus but is too large to be hand held but can be set up at golf clubs or stores. U.S. Pat. No. 2,628,496 to Wick (1953). This patent describes a hand held apparatus and utilizes a flexible circular ring through which to apply pressure against the ball along the perimeter of the ball and to also gauge sphericity.
U.S. Pat. No. 3,665,757 to Hoag (1972). This patent is an adaptation to the Atti patent but includes a circular go no-go gauge to measure ball sphericity. U.S. Pat. No. 3,653,479 to Phillips (1972). This patent is an adaptation to the Atti patent to all the apparatus to be coin actuated. U.S. Pat. No. 3,665,757 to Valebrach (1985). This patent is designated to be used to measure and sort balls in a manufacturing environment.
All of the above cited patents used the same technique to apply force to the ball under test. This technique was based on having a plate being moved a predetermined and fixed distance against the ball. This movement caused the ball to be forced against an opposing plate which was attached to a calibrated spring. A rod was affixed to this plate and extended back through the spring to contact a stem on a Dial Indicator. As the stem was moved, it rotated the dial pointer and gave a visual reading to the user. These numbers were then used to sort the balls for their rating and became the commonly accepted ratings of 80, 90 and 100. Since the harder balls will compress less than the softer balls, they will move the stem more than the softer balls and will indicate a higher number.
As a result of this technique, there are two variables involved in the testing procedure. The force applied by the spring is a function of it's Spring Rate and the distance it is depressed. This is Hooke's Law and is expressed by Force=Spring Rate.times.Distance Depressed. Therefore, as the spring is depressed, the force increases against the ball. It is also clear from the previous patents that the harder balls are compressed less than the softer balls. This results in the harder balls compressing the spring more than the softer balls and in turn this creates more force against the harder balls than against the softer balls. Because of this method, the amount of force being applied against the ball under test is variable from ball to ball. The net result is that the hardness of the ball itself plays a role in determining the amount of force being applied and thus affects the test results.
Only the U.S. Pat. No. 2,628,496 to Wick (1953) describes a hand held golf ball tester. This patent also included a method for gauging the diameter of the ball under test by providing a circular ring into which the ball must fit prior to testing. Sphericity of the ball was determined by a visual observation of how the ball fit into the ring. Balls with larger diameters would not fit and could not be tested for hardness. This patent did not provide a direct read out of the ball's compression ratings as used today but referred to the amount of "compressional force in pounds" applied to the ball and the user was left to determine how much force was good or bad.
All these patents were made using metal for the material and had many moving parts, including levers and gears for the homemade dial indicators, except for Atti which used a off-the-shelf Dial Indicator. As a result, these devices were expensive and beyond the price range a typical golfer would care to pay.
The invention described herein is different from previous patents in that the testing is accomplished by applying an identical force against all balls and this force is not a function of the ball's hardness as is the case in the previous patents. This means that the same force is applied against each ball tested and then the amount of ball compression is measured and the rating is indicated directly to the user. A large portion of this device uses modem/high strength plastics and a minimum of moving parts and therefore costs will be within the price range of interest to the average golfer.
The invention described herein is capable of measuring the sphericity of any ball by measuring the ball diameter along any number of axis and therefore the sphericity is easily determined. This invention has a self centering method for the ball and does not require the user to place or hold the ball during testing.
Objects and Advantages
With the availability of new materials and manufacturing techniques, a new type of ball has emerged, called a two piece construction or two part ball. These balls are naturally harder than the three part ball and therefore do not conform to the long accepted ratings of 90 and 100 used for the three part balls. Tests on hundreds of balls of all types, three part and two part, has shown a range of 80 to 150 with the three part balls in the lower range.
Today, a harder ball does not mean better. In fact, it is now known that a golfer should try to match his or her swing speed to the proper ball hardness for optimum feel and distance. This is evidenced by the advertisements being put out by the manufacturers.
Today, there are a number of balls being sold and with many claims for distance, control feel, etc. but the old standards of hardness rating are not longer valid and can not be used to compare balls between different manufacturers or even the different types of construction. This means that a 100 ranting from one manufacturer is not necessarily the same 100 rating from another. Many balls are not even rated.
Golfers do not all have the same swing speeds and therefore do not strike the ball with the same force. Because of this, all golfers do not compress a ball the same amount and therefore some golfers may not be able to compress the ball to its designed maximum compression and consequently will not attain the balls' maximum performance.
Play testing different balls while having a specific rating beforehand as determined by this device means that the golfer will be able to match a specific rating to those balls which provides the optimum performance for their own swing speed. This rating can then be used to evaluate new balls by comparing measured ratings; lower, equal or higher.
It is the intent of this invention to provide the golfer with a modern and accurate tool by which the golfer can measure and/or sort any type of ball and match the ball's hardness to their specific swing speed.
Using this device will provide the capability to sort balls into high, medium or low categories based on hardness thus giving the professional and low handicap players the opportunity to play very tightly controlled balls. Using the device on the course will allow the player to measure and determine when a ball ay have become degraded. "Experienced" and X-OUT balls can be measured and those not meeting the same standards for new balls can be discarded before use. Each golfer will be able to precisely determine which balls have the best feel for their swing speed and therefore use a quantified measure to select balls for future play and therefore eliminate the need to purchase new balls and play test to determine desirability.
Using this device will allow the golfer to also measure the diameter of the ball along a number of different axis and therefore allow the user to measure the sphericity of the ball.